House



R. E. HELLMUND.

SYSTEM OF CONTROL.

' APPLICATION FILED MAR. 9, 1911. v 1,347,905, Patented July 27, 1920.

3 SHEETSSHEET I.

Ground Gray/rd WITNESSES: INVENTOR Rudd/f5 He/lmoad.

I: A ATTORNEY R. E. HELLMUND.

'SYSTEM OF CONTROL APPLICATION FILED MAR. 9, 1917.

Patented July 27,1920.

3 SHEETS-SHEET 2.

Illlllll- 60 vwmso s V R51. A x

v m Mlle 1 m m w .n 5 swa 4A2 I05 a a M M/QRO s f m m Time M M Ru no 010a a M E in 0 0 o adadefa.

#4 R m N3OMMO T .0 75 5 dflz ww w a 2 Z Z a Z Z T 20 MOMMQ 5 50 00 0 0646 oye'm/may RELA Y WITNESSES:

INVENTOR Roda/f5 h'el/mwrd.

ATTORNEY R. E. HELLMUND.

SYSTEM OF CONTROL. APPLICATION FILED MAR. 9, 1917.

Patented July 27, 1920.

3 SHEETSSHEET3.

L owspec d acae/erafin Eround WITNESSES: INVENTOR around Rudolf E.b'eflm and BY 7 W RUD OLI E. HELLMII'ND;.OFISWISSVALE, PENNSYLVANIA,ASSIGNQB 'IO WESTING HOUSE ELECTRIG AN D JEANUFAGTURING COIJIEAIYY, AGQRPORATION-OF PENN- SYLVANIA.

SYSTEM..-,OF CONTROL;

Application jfilegl, March 9,

Toiall whp zt it may concern,- I

Be itknown that l, Runonr E. Hunt.- MUND, subject of theEmperor ofGermany, and a resident of Swissvale, in the county of Allegheny andState of Pennsylvanla, have invented a new. and useful lmprove ment inSystems of (lontrol of which the following is, a specificat ion.

My invention, relatesito systemsof control and especially to.directcurrent control systems for QlGCtlflCflilllWilY-VGlllQlG motorsand the like that are adapted for both a'cceleratingand regel iera-tingpperation,

The object of my invention is to provide a system of theabove-vindicated character which shall be effective; and reliable .inoperation and particularly. economical with respect tonpowerrequirements, inasmuch as rege-neratiol may ,be carriedto asubstantially. zero speed oi the momentum-driven machines .without,however requiring the usefoit certain; auxiliary machines throughout theentire I regenerative .period, as has beencustomaryin the prior art.

Mo re specifically stated it is the ob ect of my invention. to provide.a control systcm comprising a plurality of maindynanioelectricvmachinesthat are governed in accordance withthe familiarseries-parallel control during acceleration. and by parallel-seriescontrol during the regenerative period, dependentupon machine speed, a11 d,. in addition; an aux liary niotor generatoiyor booster set 18connected 1n circuit only under predetermined relatively low-speedconditions, is, atv the begin: ning of accelerating operation and at theend of the regeneratingperiod only.

My inventionlmay best be understood by refe ence to the accompanyi ngdrawings, wherein Figure 1 is a diagrammatic "VlEXV o'ii a. systernfofcontrol embodying my invention the maincircuits andtheauxiliarymachine circuits being shown; Fig, 21s a diagrammatic viewof one form of auxiliary govemingsystem ior controlling the variousswitching devices shown in Fig. 1, 1n accorcance with the sequence chaFig 3 andl ig. l; correspond to acceleration and regeneration,respectively; and Fig. 5 to Fig. 8, inclusive, Iare simplified diagramsof vario us' .sets ci connections, as indicated by theaccompanyinegends.

Reicrringto Fi g. 1, the systemshown comdescribed.

Specification of Letters Patent. Patented July 27,

ith eria -N 4. 3 5 9 switch asp-e sy familiar type, here shown conventonally tor purposes of, simplicity and clearness; a plurality oi,sWitchestOr the main and the ta lviary machine circuits LS JR, J, M; Sr;and 1 to 5; inclusive; a plurality oi main-circuit stabilizing resistors.Rl andsR2 and auxiliary-circuit resistors 6 to 10, inclusive; aplurality of limit switches L1 and L2 ior respectively governing the,operation oii switches/l and 5; avoltage relay l9; employed. underpreliminary regenerative conditions; 7 and a combined mot -generator,and e :citer set or booster set i having armatures20 to 23, inclusive,tl iat are preferably mounted upon a common shaft. 2lfor purposes to. be

The auxiliary exciting armatures 20 and 21 are respectively adapted tovariably energize the main field windings F1 and F2, respectivelythroiiighout the accelerat ing and the regenerative periods, and areprovided withsliunt field windings 25 and 26 respectively, wh ch may begoverned in common vby theresistor l0. The auxiliary motor or drivingarmature 22 is provided with a series-related field winding 27- and witha shunt field winding 28 the energization of which may be varied bysuitably manipulating theresistor 8. The auxiliary generator armaturev23 is also provided with a series-related field winding 29 and with ashunt field winding 30, the strength of which may be adjusted by thevariable resister 9. Y 1 V The general operation of the system justdescribed may bestated as follows initially, the auxiliary-motorarmature 22 is connected in series rehition with the mainseries-connected aianatures. while the auxdiary-generator armature 23 isconnected to the supply circuit to return such energy thereto as is notrequired for. accelerating the main machines and i or supplying thesmall necessary losses thereby effecting ac celerating operation withoutrequiring the use of wasteful resistors. However, as soon as apredetermined relatively low speed is attained, the booster set isexcluded from circuit, and, subsequently, series-parallel control of afamiliar type is employed for governing the main motors.

During regeneration, in general, the opposits sequence of control isutilized, namely, the machines are connected in parallel relation acrossthe supply circuit, under suitable highs ieed and voltage conditions,parallel-series control is then employed to effect regeneration until arelatively low machine speed is reached, and then the booster set isagain fully included in circuit to thus effect a continuation ofregenerative operation until the main-machine speed is substantiallyzero. Thus, main-cir cuit accelerating resistors are eliminated, and arelatively large percentage of the kinetic energy of the momentum-drivenmachines and vehicle is returned to the supply circuit; but the boosterset is included in circuit for only a relatively small portion of theoperating time and never carries a relatively heavy current, since it isconnected in circuit with the main machines only when they are connectedin series relation. Consequently, the initial cost and weight and theoperating expenses of the booster set are correspondingly low.

Reference may now be had to Fig. 2, wherein the auxiliary governingsystem shown comprises the actuating coils of the variouscircuit-governing switches shown in Fig. 1; and the variable resistors8, 9 and 10 which, together with the various actuating coils, areadapted to be suitably governed by a master controller MC that isadapted to occupy a plurality of operative positions a to j, inclusive,when moved in one direction corresponding to acceleration, and aplurality of operative positions a to 9 when actuated in the otherdirection that corre sponds to regeneration, a battery 13 or othersuitable source of energy being employed for the purpose of exciting thevarious actuating coils.

rlissuming that it is desired to effect acceleration of the mainmachines, the master rontroller ll (3 may be actuated to its initialoperative position a, whereupon one circuit is established from thepositive terminal 13+ of the battery 13, through conductor 10, conirolfing as 41 and which are bridged by contact segment 1-3 of the mastercontroller the actuating coil of the switch LS and conductor a l to thenegative battery terminal 13-.

Another circuit is completed at this time from the contact segment 43,through control finger 4:5 and the actuating coil of the switch JR, tothe negative conductor 44.

Further circuits are simultaneously completed by the engagement oi thecontact segment 43 with control fingers 46 and 47,

whence circuits are respectively continued 'through the actuating coilsof the switches 2 and 3 to the negative conductor l i.

Referring temporarily to Fig. 1, the circuits established by the closureof the above mentioned switches may be traced as follows: from thetrolley through conductor 50, switchLS, actuating coil 51 of the limitswitch or relay L1, main armature A1, stabilizing resistor R1, conductor52, switch (ill, conductor 53, stabilizing resistor R2, conductor 5 mainarmature A2, conductor 55, actuating coil 56 of the limit switch L2,conductors 57 and 58, switch 2, conductor 59, the auxiliary motorarmature 22 and its series-related field winding 27, and conductors (30and G1 to the negative supply-circuit conductor ground.

An auxiliary-machine circuit is established from the trolley throughconductor (32, suitable switch 63, conductors (it, and G5, the shuntfield winding 28 for the auxilia y motor armature 22, conductors G7 andG8, switch 3 and conductor 69 to ground.

One terminal of the auxiliary generator armature 25-3 is connected,through conductor 70, to the positively-energized conductor (55, whilethe other terminal thereof is connected, through the correspondingseries-related field winding 29 and conductor 71, to the negativeconductor 61. The shunt field winding 30 for the auxiliarygeneratorarmature 23 has one terminal connected to the positively-energizedconductor 70 and its other terminal connected through conductors 72 and73 to ground.

One brush of the auxiliary exciting armature 20 is connected toconductor 75, whence circuit is completed through the intermittentlyshort-circuited resistor 6, conductor 76, stabilizing resistor R1,conductors 77 and 78, the reversing switch RS and the main field windingF1, in accordance with the usual custom, and conductor 79 to theopposite terminal of the exciting armature 20. One terminal of the othere 'citing armature 21 is connected, through conductor 80, intermittentlyshort-circuited resistor 7, conductor 81, stabilizing resistor R2,conductor 82, reversing switch RS and main field winding F2, andconductor 83, to the other terminal. The field-winding circuits for theexciting armatures 20 and 21 are established from thepositively-energized conductor 64, through conductor 84:, tojunction-point 85, thence, through the parallel-related field windings25 and 26 for the respective exciting armatures 20 and 21, tojunction-point 86, from which point circuit is completed throughconductors 8'7 and 88 to the nega tive supply-circuit conductor ground.

Thus, as illustrated in the simplified diagram, Fig. 5, theauxiliary-motor armature 22 is initially connected in series relationwith the main machines and is strongly enply i circuit b ergized tothereby absorb the greater part of the supply-circuit voltageiand efiectthe impression upon the main machines of a suitably low electromotiveforce for starting them into operation. The accelerating'energy that isnot utilized for supplying necessary operating losses is returned to thesupthe auxiliary-generator armature 23. [he excitation of the auxiliaryexciting armaturesQO and 21' is also. relatively great, therebyproducing aycorre-- spondingly .strong field-winding excitation for themainmachines, under starting "conditions;

' Upon actuation of the master controller MO (Fig 2), through themultit-notchpo- 'sition b, a series of control fingers 89 that areconnected to suitable points of the aux- -iliary resistor -81are.gradually disengaged from the Contact segment iiitothereby includeincreasingamounts of the resistor 8' 28 in circuit with the shuntfieldwindin for the auxillary-motor armature '22. hus, the auxiliarymotor voltage is gradually reduced to correspondingly increase thevoltage applied to the main machines and thus effect an increase'ofspeed thereof.

In position 0 of the master controller, the resistor 10 is graduallyinserted. in circuit with the field windings 25. and 26 for the ex- 7citing armatures 2O a'ndQl, thereby corre- 'spondingiy weakening themain-fielctwinding excitation to cause an increase. in the speed of themain machines in accordance with familiar principles. i

In position d, the contact segment 13 first engagescontrol finger 92,whence circuit is completed through the actuating coil of the switch lto the negative battery conductor 44:. Thus the auxiliary motorarmature22 which, at this time, has impressed 11113011 it a negligible voltage,is shortcircuited and entirely excluded. from further operation duringthe accelerating -period 7 r v A further auxiliary circuit Y is:fcompleted in position (Z of the master controller bythe engagement ofcontrol finger! 93 with the contact segment 43 'toeriect theexcitationof the actuating coil of the switch J The actuating coil of the switchJR is thereupon ,cleenergized 'byjthe disengagementof coni. trol finger45 from the-contact-segment 43.

in position e,'contact segment 43 first engages control fingers 9i and95. whereb the actuating coils oftheswitches M andorare energized andthe actuating coil -of the switch J is-thereupon 'denergizledq,Furthermore, swit'chesQ and 3 are opened by reason of the deenergization of their actuating 'coils in position ,6 and thus theauxiliarymotor armature 22 andfits field w1nd1ng;28

are entirely disconnected from circuit to thereby reduce the losseslinthem'otor -genmature" 23 actingas a motor.

erator set. which is now. drivenby the armain-circuit connectionsproduced by the closure of switches'M and G and the concurrent openingof switches J R and J it is believed that the arrangement of maincircuits will be fully understood from Fig. 6, inasmuch as the operationoutlined consti tutes the familiar bridging type of se-V ries-paralleltransition. i

To further effect acceleration of themain machines after their initialconnection in parallel relation, the contact segment 45 againsuccessively breaks contact with the control fingers 91 to thusgradually include the auxiliary resistor 10 in circuit with the V fieldwindings of the exciting. armatures '20 and 21 and thereby reduce themain fieldwinding excitation, as previously set forth.

Throughout the entire accelerating op eration, switches 4i and 5., whichnormally short-circuit the vresistors 6 and 7, respec tively, aregoverned by the limit switches L1 and L2, which are responsive tomaincircuit currentv conditions, thus including the resistors 6, and 7incircuit with the corresponding auxiliary. exciting armatures whenevera relatively high main-armature currentobtains to reduce the main fieldex-.

negative conductor 44. Similarly, a circuit iscompleted from controlfinger 100, which corresponds to the control finger 96, throughconductor 101, cooperating contact members 102 of the limit switch L2 inits upper position, conductor 103 and the actuating coil of the switch 5tO. CO11Cl\1CtO1-fii. In this way-, relatively.greatsurges orvariationsof I accelerating current are automatically prevented. 1

Assumingthat conditions ,aresuitable iorr regenerative brakingoperation, the master controller is first returned to its off position,and'the maincircuit reversing switch RS is then actuated to its reversedposition for a familiar'purpose. By actuating the. master; controller toits initial regenerative position a, switches M, G and 1 are firstclosedby. reason of the 'engagement'of a contactsegment 109 of themaster controller with the corresponding control fingers 94,; :95-and92." j 3 q The switch LS isnot closed to connect the momentum-drivenmachines to the supply circuit until the voltage of the armatures A1 andA2 has been built up.throughsuitable field excitation from theauxiliary-ex iting p the actuating coil of the switch LS tonegaimmediately ellects tive conductor 44. As soon as the switch Lt) hasclosed, an auxiliary electrical interlock Lil-in, which is associatedwith, and actuated by, the switch LS, in accordance with a familiarpractice, bridges the auxiliary contact members 111, thereby renderingthe v closure of the switchLS subsequently independent of the operationof the voltage relay 19. See simplified diagram Fig. 7.

A brief exposition of the ch1etlunct1on' of the stablilizingresistorsltl and R2 will be of value. By reason of the peculiar circuitconnections, eachresistor carries the corresponding combinedmain-armature and exciting-armature, or main field-winding, currents. Inthe case of an incipient increase of main-armature or regenerativecurrent, therefore, the augmented voltage drop across the correspondingstabilizing resistor reduction of the voltage available for delivery tothe main field winding from the allied exciting armature, therebycausing a reduction of the rege erative current to a dcsirednormalvalue. Conversely, an incipient decrease of main-armature currentproduces an inherent increase of. main field-winding current. Thus, theregenerative current is maintained substantially constant, irrespectiveof supply-cin Quit-voltage fluctuations and the like. The system justset forth is fully described in my co-pending application, Se ial No.44,443, filed Aug. 9, 1915,.patented Aprill, 1919, No. 1,298,706.

Upon movement of the master controller thrmligh its multi-notch position0', the resistor 10 is gradually short-circuited to thereary by increasethe excitation of the aux field windings 25 and 26 and correspondinglyaugment the energization of the main lield windings F1 and F2, as thespeed oi the main machines decreases. Positions 0 and 03 are transitionnotches wherein the main machines are gr dually changed over to seriesrelation by the closure of switch J, the opening of switches M and G,the closure of switch JR and the opening of switch J, thus effecting anuninterrupted transition from parallel to series relation withoutproducing any undue current surges.

In position 6, the resistor 10-is again gradually short-circuited tocorrespondingly increase the excitation of the main field windingsafter'the series connectionof the main machines to compensate for thespeed decrease thereof. in poslt on 7", switch 1 is opened by reason ofthe disengagement of the contact segment 109 from thecontrol linger 92just after the engagement of the contact segment with control lingers4:6 and N to ellect the closure of switches 2 and 3. Thus, the boosterset is again fully included in circuit, the auxiliary armature 22absorbing the necessary portion oil the full voltage in order tomaintain regenerative operation of the main machine. See Fig. 8.

To continue regeneration until a substantially zero main-machine speedis attained, the resistor Sis gradually excltuled from circuit in1nulti-notch position 9 of the master controller and thus the voltage ofthe auxiliary armature 221's gradually increased to compensate 'l or thecorresponding decrease of. main-machine. voltage and speed until asubstantially zero speed of the main machines obtains.

Throughout the regenerative period also, the switches 4 and 5 aregoverned by the limit switches L1 and L2 to prevent surges ofregenerative current, in the manner previously described.

I do not wish to be restricted to the specifie circuit connections orarrangement of parts herein set forth, as various modifica tions thereofmay be ellected without departing'from the spirit and scope of my in-:vention. I desire, therefore, that only such limitations shall beimposed as are indicated in the appended claims.

I claim as my invention:

1. In a system of control, the combination with a supply circuit, and aplurality of 'main dynamo-electric machines adapted for bothacceleration and regeneration, oi an auxiliary booster set, means foreffecting series-parallel control of the main machines, and means forconnecting one of the booster-set machines in series-circuit relationwith the main machines and another in parallel-circuit relation theretoonly under conditions of relatively low accelerating or regeneratingmain-machine speed.

' 2. In a system of control, the combination with a supply circuit, anda plurality of main dynamo-electric machines, of an auxiliary boosterset, means for effecting series-parallel accelerating control andparallel-series regenerative control of the main machines I abovepredetermined machinespeed conditions, and means for connecting one ofthe booster-set machines in seriescircuit relation with the'mainmachines and another in parallel-circuit relation thereto whenever themachines are below predeter-' mined speed conditions.

3. In a system of control, the combination with a supply circuit, and aplurality of main dynamo-electric machines, of auxiliary exciting meansfor the main-machine field windings, auxiliary dynamo-electric means torvarying the relation o1 supply-circuit and main-machine voltage, meansfor em-' ploying said dynamo-electric means during only predeterminedoperating conditions, and means for effecting series-parallel controlofthe main machines under all other conditions.

- .4. In a system of control, the combination with a supply circuit, anda plurality of main dynamo-electric machines, of auxiliary excitingmeans for the main-machine-field windings, auxiliary dynamo-electricmachines respectivelyadapted for connection in chines rotatable with thefirst mentioned auxiliary machines and respectively adapted forconnection in series relation with, and in parallel relation to, themain machines, means for employing said other auxiliary machines onlyunder relatively low-speed accelerating and regenerating conditions to vditions series relation with and in parallel relation vary the relationsof supply-circuit and main-machinev voltages, v and means for effectingseries-parallel accelerating control and parallel-series regeneratingcontrol of the main machines for higher-speed condiions.

6. In a system of control, the combination Witha supply circuit, and aplurality of main dynamo-electric machines, of an auxiliary booster set,means for connectingv one of the booster-set machines inseries re-.lation with the main machines and another in parallel relation theretoonly under. conof relatively V low-main-machine speed to vary therelations of supply-circuit and i'nain-n'ia'chine voltages, and-meansfor effecting seriesparallel control of the main-machines forhigher-speed conditions.

7. In a system of control, the combination with a supply circuit, and aplurality of main dynamo-electric machines adapted for both accelerationand regeneration, of an auxiliary motor-generator set, means foreffecting series-parallel control of the main machines, and means forconnecting one. of

the auxiliary machines in series-circuit relation with the main machinesonly under conditions of relatively low accelerating and regeneratingmain-machine speed. V

In testimony whereof I have hereunto subscribed my name this 28th day ofFeb, '1917.

aUDoLr E. HELLMUND.

